Poly Aluminum Chloride (PAC)
Poly Aluminum Chloride (PAC) is an inorganic polymer coagulant used extensively for water treatment and purification. It is a highly efficient flocculating agent, derived from aluminum salts and partially neutralized with chloride, forming polymerized aluminum complexes. PAC is preferred over traditional alum for its rapid floc formation, broader pH range, and lower sludge production. Available in both liquid and powder forms, it is widely applied in municipal, industrial, and commercial sectors for clarification, separation, and purification processes.
Municipal Water Treatment
Used to purify drinking water by removing turbidity, suspended solids, and pathogens.
Offers superior performance over alum at low temperatures and varying pH levels.
Reduces aluminum residuals in treated water, making it safer for consumption.
Wastewater Treatment
Commonly applied in sewage and industrial wastewater plants to remove color, heavy metals, organic matter, and suspended particles.
Effective in the treatment of oily and high-COD wastewater (e.g., textile, leather, chemical industries).
Helps in sludge thickening and dewatering processes.
Paper Industry
Used in paper sizing and retention systems to enhance paper strength and reduce fiber loss.
Improves retention of fillers and fines, resulting in better paper quality and machine efficiency.
Textile & Dyeing Industry
Employed to remove anionic dyes, reduce BOD/COD levels, and clarify colored effluents.
Provides excellent color removal efficiency in synthetic and reactive dye wastewater.
Oil & Gas Industry
Used in oilfield water treatment to remove emulsified oil and suspended solids.
Functions as a flocculant in drilling fluid clarification and produced water treatment.
Cosmetic & Pharmaceutical Water Purification
In pre-treatment stages for ultra-pure water systems.
Ensures removal of particles and bacteria prior to membrane filtration.
Secondary Uses
Swimming Pool Water Treatment
Helps in clarifying pool water by flocculating fine particles and impurities.
Reduces chlorine demand by removing organics.
Mining & Metallurgy
Used in ore washing and separation processes, and for treating tailing water.
Assists in removing heavy metals and improving water reuse.
Food & Beverage Industry
Applied in water treatment for bottled water plants and beverage production, under regulated conditions.
Ensures microbial safety and visual clarity.
Sugar Industry
Utilized to purify cane juice by removing colloidal particles during juice clarification.
Helps in reducing scaling in evaporators.
Tanning Industry
Employed in effluent treatment to remove chromium, fats, and dyes.
Assists in water recycling systems in leather processing.
Basic Identification Attributes
Chemical Name (IUPAC): Poly(aluminum chloride)
Common/Trade Name: PAC
CAS Number: 1327-41-9
HS Code: 2827.49.00 (Chlorides of aluminum)
Synonyms: Polyaluminium chloride; PACL; Basic aluminum chloride
Physical & Chemical Properties
Physical State: Available in powder or liquid form
Color & Odor: Light yellow to white (powder); odorless
pH (1% solution): ~3.5–5.0
Solubility: Completely soluble in water
Al₂O₃ Content: 28–31% (for high-grade powder)
Basicity: 40–90% depending on grade
Density (Liquid): ~1.2 g/cm³
Safety & Hazard Attributes
GHS Classification: Not classified as hazardous
Toxicity: Low toxicity; avoid ingestion and contact with eyes or skin
Exposure Limits: Use appropriate precautions in case of prolonged exposure
Storage & Handling Attributes
Storage Conditions: Store in cool, dry, and well-ventilated area; avoid moisture for powdered form
Container Type: HDPE drums, IBC totes, or moisture-proof bags for powder
Shelf Life:
Liquid: 6–12 months
Powder: Up to 24 months if sealed properly
Handling Precautions: Use gloves and eye protection during handling; avoid inhaling powder dust
Regulatory & Compliance Attributes
Complies with:
NSF/ANSI 60 for drinking water additives (select grades)
ISO standards for water treatment chemicals
REACH registered (for industrial use in EU)
Environmental & Health Impact
Biodegradability: Inorganic – not biodegradable but environmentally stable
Ecotoxicity: Low at recommended dosages
Sludge Reduction: Produces less sludge compared to traditional alum
Bioaccumulation: Not expected
Safety Handling Precautions
PPE Required: Safety goggles, gloves, and dust mask (for powder)
Handling Guidelines: Avoid direct skin contact and inhalation; handle with care in damp environments
Storage Measures: Keep container tightly sealed; store off the floor to avoid moisture contact
First Aid Measures
Inhalation: Move to fresh air; seek medical help if symptoms persist
Skin Contact: Rinse with water and soap; seek medical attention for irritation
Eye Contact: Flush eyes with plenty of water for at least 15 minutes
Ingestion: Rinse mouth; do not induce vomiting; seek immediate medical help
Firefighting Measures
Fire Hazards: Non-flammable
Extinguishing Media: Use water spray, foam, or dry chemical (for surrounding fire)
Special Precautions: Use protective gear; avoid contact with spilled material
Hazardous Combustion Products: May release hydrochloric acid fumes at high temperatures